streaming-markdown

0.2.15 verified Sat May 09 auth: no javascript

Streaming Markdown parser for incremental rendering of markdown as it's written, targeting AI chat-style outputs. Current version 0.2.15. Actively developed with experimental features. Ships TypeScript types. Key differentiator: optimistic parsing – immediately renders partial tokens (e.g., inline code, bold) without waiting for closing markers, supporting selectable text during streaming. The library exposes a custom Renderer interface for DOM control, with built-in default renderer and logger renderer. Minimal bundle size (~3 kB gzipped). Requires Node >=20 for server-side use.

Common errors

error SyntaxError: The requested module 'streaming-markdown' does not provide an export named 'default' ↓

cause Trying to default import from an ESM-only module that only exports named exports.

fix

Use named imports: import { parser } from 'streaming-markdown'

error Error: Cannot find module 'streaming-markdown' ↓

cause Package not installed or running in an unsupported environment (e.g., Node <20).

fix

Install with npm install streaming-markdown and ensure Node >=20.

error TypeError: smd.default_renderer is not a function ↓

cause Importing wrong symbol or using a version prior to v0.0.15 where the function existed.

fix

Verify the correct import: import { default_renderer } from 'streaming-markdown'

Warnings

gotcha Parser is experimental; markdown features may be incomplete or behave unexpectedly. ↓

fix Check the GitHub README for supported features before relying on it in production.

breaking In v0.0.15, the attribute for code blocks changed from 'lang' to 'class'. Custom renderers relying on 'lang' will break. ↓

fix Update custom renderers to use 'class' attribute for language.

gotcha Node >=20 required. Older versions will cause runtime errors. ↓

fix Upgrade Node.js to version 20 or later.

gotcha The package is ESM-only; CommonJS require() will fail. ↓

fix Use import statements or switch to ESM in your project.

Install

npm install streaming-markdown

yarn add streaming-markdown

pnpm add streaming-markdown

Imports

parser

wrong

import parser from 'streaming-markdown'

correct

import { parser } from 'streaming-markdown'

ESM-only module, default export is not available. Use named imports.

default_renderer

wrong

const { default_renderer } = require('streaming-markdown')

correct

import { default_renderer } from 'streaming-markdown'

CommonJS require() not supported; use ESM imports.

parser_write
wrong
```
import { write } from 'streaming-markdown'
```
correct
```
import { parser_write } from 'streaming-markdown'
```
Function is named parser_write, not write. Check documentation for exact exports.

Quickstart

Demonstrates creating a parser with default_renderer, writing markdown chunks, and ending the stream.

import * as smd from 'streaming-markdown';

const element = document.getElementById('output');
const renderer = smd.default_renderer(element);
const parser = smd.parser(renderer);

smd.parser_write(parser, "# Hello ");
smd.parser_write(parser, "World\n\n");
smd.parser_write(parser, "This is **bold** and *italic* text.");
smd.parser_end(parser);